1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * This file contains the procedures for the h 3 * This file contains the procedures for the handling of select and poll
4 * 4 *
5 * Created for Linux based loosely upon Mathiu 5 * Created for Linux based loosely upon Mathius Lattner's minix
6 * patches by Peter MacDonald. Heavily edited 6 * patches by Peter MacDonald. Heavily edited by Linus.
7 * 7 *
8 * 4 February 1994 8 * 4 February 1994
9 * COFF/ELF binary emulation. If the proce 9 * COFF/ELF binary emulation. If the process has the STICKY_TIMEOUTS
10 * flag set in its personality we do *not* 10 * flag set in its personality we do *not* modify the given timeout
11 * parameter to reflect time remaining. 11 * parameter to reflect time remaining.
12 * 12 *
13 * 24 January 2000 13 * 24 January 2000
14 * Changed sys_poll()/do_poll() to use PAG 14 * Changed sys_poll()/do_poll() to use PAGE_SIZE chunk-based allocation
15 * of fds to overcome nfds < 16390 descrip 15 * of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian).
16 */ 16 */
17 17
18 #include <linux/compat.h> 18 #include <linux/compat.h>
19 #include <linux/kernel.h> 19 #include <linux/kernel.h>
20 #include <linux/sched/signal.h> 20 #include <linux/sched/signal.h>
21 #include <linux/sched/rt.h> 21 #include <linux/sched/rt.h>
22 #include <linux/syscalls.h> 22 #include <linux/syscalls.h>
23 #include <linux/export.h> 23 #include <linux/export.h>
24 #include <linux/slab.h> 24 #include <linux/slab.h>
25 #include <linux/poll.h> 25 #include <linux/poll.h>
26 #include <linux/personality.h> /* for STICKY_T 26 #include <linux/personality.h> /* for STICKY_TIMEOUTS */
27 #include <linux/file.h> 27 #include <linux/file.h>
28 #include <linux/fdtable.h> 28 #include <linux/fdtable.h>
29 #include <linux/fs.h> 29 #include <linux/fs.h>
30 #include <linux/rcupdate.h> 30 #include <linux/rcupdate.h>
31 #include <linux/hrtimer.h> 31 #include <linux/hrtimer.h>
32 #include <linux/freezer.h> 32 #include <linux/freezer.h>
33 #include <net/busy_poll.h> 33 #include <net/busy_poll.h>
34 #include <linux/vmalloc.h> 34 #include <linux/vmalloc.h>
35 35
36 #include <linux/uaccess.h> 36 #include <linux/uaccess.h>
37 37
38 38
39 /* 39 /*
40 * Estimate expected accuracy in ns from a tim 40 * Estimate expected accuracy in ns from a timeval.
41 * 41 *
42 * After quite a bit of churning around, we've 42 * After quite a bit of churning around, we've settled on
43 * a simple thing of taking 0.1% of the timeou 43 * a simple thing of taking 0.1% of the timeout as the
44 * slack, with a cap of 100 msec. 44 * slack, with a cap of 100 msec.
45 * "nice" tasks get a 0.5% slack instead. 45 * "nice" tasks get a 0.5% slack instead.
46 * 46 *
47 * Consider this comment an open invitation to 47 * Consider this comment an open invitation to come up with even
48 * better solutions.. 48 * better solutions..
49 */ 49 */
50 50
51 #define MAX_SLACK (100 * NSEC_PER_MSEC) 51 #define MAX_SLACK (100 * NSEC_PER_MSEC)
52 52
53 static long __estimate_accuracy(struct timespe 53 static long __estimate_accuracy(struct timespec64 *tv)
54 { 54 {
55 long slack; 55 long slack;
56 int divfactor = 1000; 56 int divfactor = 1000;
57 57
58 if (tv->tv_sec < 0) 58 if (tv->tv_sec < 0)
59 return 0; 59 return 0;
60 60
61 if (task_nice(current) > 0) 61 if (task_nice(current) > 0)
62 divfactor = divfactor / 5; 62 divfactor = divfactor / 5;
63 63
64 if (tv->tv_sec > MAX_SLACK / (NSEC_PER 64 if (tv->tv_sec > MAX_SLACK / (NSEC_PER_SEC/divfactor))
65 return MAX_SLACK; 65 return MAX_SLACK;
66 66
67 slack = tv->tv_nsec / divfactor; 67 slack = tv->tv_nsec / divfactor;
68 slack += tv->tv_sec * (NSEC_PER_SEC/di 68 slack += tv->tv_sec * (NSEC_PER_SEC/divfactor);
69 69
70 if (slack > MAX_SLACK) 70 if (slack > MAX_SLACK)
71 return MAX_SLACK; 71 return MAX_SLACK;
72 72
73 return slack; 73 return slack;
74 } 74 }
75 75
76 u64 select_estimate_accuracy(struct timespec64 76 u64 select_estimate_accuracy(struct timespec64 *tv)
77 { 77 {
78 u64 ret; 78 u64 ret;
79 struct timespec64 now; 79 struct timespec64 now;
80 u64 slack = current->timer_slack_ns; <<
81 80
82 if (slack == 0) !! 81 /*
>> 82 * Realtime tasks get a slack of 0 for obvious reasons.
>> 83 */
>> 84
>> 85 if (rt_task(current))
83 return 0; 86 return 0;
84 87
85 ktime_get_ts64(&now); 88 ktime_get_ts64(&now);
86 now = timespec64_sub(*tv, now); 89 now = timespec64_sub(*tv, now);
87 ret = __estimate_accuracy(&now); 90 ret = __estimate_accuracy(&now);
88 if (ret < slack) !! 91 if (ret < current->timer_slack_ns)
89 return slack; !! 92 return current->timer_slack_ns;
90 return ret; 93 return ret;
91 } 94 }
92 95
93 96
94 97
95 struct poll_table_page { 98 struct poll_table_page {
96 struct poll_table_page * next; 99 struct poll_table_page * next;
97 struct poll_table_entry * entry; 100 struct poll_table_entry * entry;
98 struct poll_table_entry entries[]; 101 struct poll_table_entry entries[];
99 }; 102 };
100 103
101 #define POLL_TABLE_FULL(table) \ 104 #define POLL_TABLE_FULL(table) \
102 ((unsigned long)((table)->entry+1) > P 105 ((unsigned long)((table)->entry+1) > PAGE_SIZE + (unsigned long)(table))
103 106
104 /* 107 /*
105 * Ok, Peter made a complicated, but straightf 108 * Ok, Peter made a complicated, but straightforward multiple_wait() function.
106 * I have rewritten this, taking some shortcut 109 * I have rewritten this, taking some shortcuts: This code may not be easy to
107 * follow, but it should be free of race-condi 110 * follow, but it should be free of race-conditions, and it's practical. If you
108 * understand what I'm doing here, then you un 111 * understand what I'm doing here, then you understand how the linux
109 * sleep/wakeup mechanism works. 112 * sleep/wakeup mechanism works.
110 * 113 *
111 * Two very simple procedures, poll_wait() and 114 * Two very simple procedures, poll_wait() and poll_freewait() make all the
112 * work. poll_wait() is an inline-function de 115 * work. poll_wait() is an inline-function defined in <linux/poll.h>,
113 * as all select/poll functions have to call i 116 * as all select/poll functions have to call it to add an entry to the
114 * poll table. 117 * poll table.
115 */ 118 */
116 static void __pollwait(struct file *filp, wait 119 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
117 poll_table *p); 120 poll_table *p);
118 121
119 void poll_initwait(struct poll_wqueues *pwq) 122 void poll_initwait(struct poll_wqueues *pwq)
120 { 123 {
121 init_poll_funcptr(&pwq->pt, __pollwait 124 init_poll_funcptr(&pwq->pt, __pollwait);
122 pwq->polling_task = current; 125 pwq->polling_task = current;
123 pwq->triggered = 0; 126 pwq->triggered = 0;
124 pwq->error = 0; 127 pwq->error = 0;
125 pwq->table = NULL; 128 pwq->table = NULL;
126 pwq->inline_index = 0; 129 pwq->inline_index = 0;
127 } 130 }
128 EXPORT_SYMBOL(poll_initwait); 131 EXPORT_SYMBOL(poll_initwait);
129 132
130 static void free_poll_entry(struct poll_table_ 133 static void free_poll_entry(struct poll_table_entry *entry)
131 { 134 {
132 remove_wait_queue(entry->wait_address, 135 remove_wait_queue(entry->wait_address, &entry->wait);
133 fput(entry->filp); 136 fput(entry->filp);
134 } 137 }
135 138
136 void poll_freewait(struct poll_wqueues *pwq) 139 void poll_freewait(struct poll_wqueues *pwq)
137 { 140 {
138 struct poll_table_page * p = pwq->tabl 141 struct poll_table_page * p = pwq->table;
139 int i; 142 int i;
140 for (i = 0; i < pwq->inline_index; i++ 143 for (i = 0; i < pwq->inline_index; i++)
141 free_poll_entry(pwq->inline_en 144 free_poll_entry(pwq->inline_entries + i);
142 while (p) { 145 while (p) {
143 struct poll_table_entry * entr 146 struct poll_table_entry * entry;
144 struct poll_table_page *old; 147 struct poll_table_page *old;
145 148
146 entry = p->entry; 149 entry = p->entry;
147 do { 150 do {
148 entry--; 151 entry--;
149 free_poll_entry(entry) 152 free_poll_entry(entry);
150 } while (entry > p->entries); 153 } while (entry > p->entries);
151 old = p; 154 old = p;
152 p = p->next; 155 p = p->next;
153 free_page((unsigned long) old) 156 free_page((unsigned long) old);
154 } 157 }
155 } 158 }
156 EXPORT_SYMBOL(poll_freewait); 159 EXPORT_SYMBOL(poll_freewait);
157 160
158 static struct poll_table_entry *poll_get_entry 161 static struct poll_table_entry *poll_get_entry(struct poll_wqueues *p)
159 { 162 {
160 struct poll_table_page *table = p->tab 163 struct poll_table_page *table = p->table;
161 164
162 if (p->inline_index < N_INLINE_POLL_EN 165 if (p->inline_index < N_INLINE_POLL_ENTRIES)
163 return p->inline_entries + p-> 166 return p->inline_entries + p->inline_index++;
164 167
165 if (!table || POLL_TABLE_FULL(table)) 168 if (!table || POLL_TABLE_FULL(table)) {
166 struct poll_table_page *new_ta 169 struct poll_table_page *new_table;
167 170
168 new_table = (struct poll_table 171 new_table = (struct poll_table_page *) __get_free_page(GFP_KERNEL);
169 if (!new_table) { 172 if (!new_table) {
170 p->error = -ENOMEM; 173 p->error = -ENOMEM;
171 return NULL; 174 return NULL;
172 } 175 }
173 new_table->entry = new_table-> 176 new_table->entry = new_table->entries;
174 new_table->next = table; 177 new_table->next = table;
175 p->table = new_table; 178 p->table = new_table;
176 table = new_table; 179 table = new_table;
177 } 180 }
178 181
179 return table->entry++; 182 return table->entry++;
180 } 183 }
181 184
182 static int __pollwake(wait_queue_entry_t *wait 185 static int __pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
183 { 186 {
184 struct poll_wqueues *pwq = wait->priva 187 struct poll_wqueues *pwq = wait->private;
185 DECLARE_WAITQUEUE(dummy_wait, pwq->pol 188 DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task);
186 189
187 /* 190 /*
188 * Although this function is called un 191 * Although this function is called under waitqueue lock, LOCK
189 * doesn't imply write barrier and the 192 * doesn't imply write barrier and the users expect write
190 * barrier semantics on wakeup functio 193 * barrier semantics on wakeup functions. The following
191 * smp_wmb() is equivalent to smp_wmb( 194 * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
192 * and is paired with smp_store_mb() i 195 * and is paired with smp_store_mb() in poll_schedule_timeout.
193 */ 196 */
194 smp_wmb(); 197 smp_wmb();
195 pwq->triggered = 1; 198 pwq->triggered = 1;
196 199
197 /* 200 /*
198 * Perform the default wake up operati 201 * Perform the default wake up operation using a dummy
199 * waitqueue. 202 * waitqueue.
200 * 203 *
201 * TODO: This is hacky but there curre 204 * TODO: This is hacky but there currently is no interface to
202 * pass in @sync. @sync is scheduled 205 * pass in @sync. @sync is scheduled to be removed and once
203 * that happens, wake_up_process() can 206 * that happens, wake_up_process() can be used directly.
204 */ 207 */
205 return default_wake_function(&dummy_wa 208 return default_wake_function(&dummy_wait, mode, sync, key);
206 } 209 }
207 210
208 static int pollwake(wait_queue_entry_t *wait, 211 static int pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
209 { 212 {
210 struct poll_table_entry *entry; 213 struct poll_table_entry *entry;
211 214
212 entry = container_of(wait, struct poll 215 entry = container_of(wait, struct poll_table_entry, wait);
213 if (key && !(key_to_poll(key) & entry- 216 if (key && !(key_to_poll(key) & entry->key))
214 return 0; 217 return 0;
215 return __pollwake(wait, mode, sync, ke 218 return __pollwake(wait, mode, sync, key);
216 } 219 }
217 220
218 /* Add a new entry */ 221 /* Add a new entry */
219 static void __pollwait(struct file *filp, wait 222 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
220 poll_table *p) 223 poll_table *p)
221 { 224 {
222 struct poll_wqueues *pwq = container_o 225 struct poll_wqueues *pwq = container_of(p, struct poll_wqueues, pt);
223 struct poll_table_entry *entry = poll_ 226 struct poll_table_entry *entry = poll_get_entry(pwq);
224 if (!entry) 227 if (!entry)
225 return; 228 return;
226 entry->filp = get_file(filp); 229 entry->filp = get_file(filp);
227 entry->wait_address = wait_address; 230 entry->wait_address = wait_address;
228 entry->key = p->_key; 231 entry->key = p->_key;
229 init_waitqueue_func_entry(&entry->wait 232 init_waitqueue_func_entry(&entry->wait, pollwake);
230 entry->wait.private = pwq; 233 entry->wait.private = pwq;
231 add_wait_queue(wait_address, &entry->w 234 add_wait_queue(wait_address, &entry->wait);
232 } 235 }
233 236
234 static int poll_schedule_timeout(struct poll_w 237 static int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
235 ktime_t *expires, un 238 ktime_t *expires, unsigned long slack)
236 { 239 {
237 int rc = -EINTR; 240 int rc = -EINTR;
238 241
239 set_current_state(state); 242 set_current_state(state);
240 if (!pwq->triggered) 243 if (!pwq->triggered)
241 rc = schedule_hrtimeout_range( 244 rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
242 __set_current_state(TASK_RUNNING); 245 __set_current_state(TASK_RUNNING);
243 246
244 /* 247 /*
245 * Prepare for the next iteration. 248 * Prepare for the next iteration.
246 * 249 *
247 * The following smp_store_mb() serves 250 * The following smp_store_mb() serves two purposes. First, it's
248 * the counterpart rmb of the wmb in p 251 * the counterpart rmb of the wmb in pollwake() such that data
249 * written before wake up is always vi 252 * written before wake up is always visible after wake up.
250 * Second, the full barrier guarantees 253 * Second, the full barrier guarantees that triggered clearing
251 * doesn't pass event check of the nex 254 * doesn't pass event check of the next iteration. Note that
252 * this problem doesn't exist for the 255 * this problem doesn't exist for the first iteration as
253 * add_wait_queue() has full barrier s 256 * add_wait_queue() has full barrier semantics.
254 */ 257 */
255 smp_store_mb(pwq->triggered, 0); 258 smp_store_mb(pwq->triggered, 0);
256 259
257 return rc; 260 return rc;
258 } 261 }
259 262
260 /** 263 /**
261 * poll_select_set_timeout - helper function t 264 * poll_select_set_timeout - helper function to setup the timeout value
262 * @to: pointer to timespec64 variable 265 * @to: pointer to timespec64 variable for the final timeout
263 * @sec: seconds (from user space) 266 * @sec: seconds (from user space)
264 * @nsec: nanoseconds (from user space) 267 * @nsec: nanoseconds (from user space)
265 * 268 *
266 * Note, we do not use a timespec for the user 269 * Note, we do not use a timespec for the user space value here, That
267 * way we can use the function for timeval and 270 * way we can use the function for timeval and compat interfaces as well.
268 * 271 *
269 * Returns -EINVAL if sec/nsec are not normali 272 * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0.
270 */ 273 */
271 int poll_select_set_timeout(struct timespec64 274 int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec)
272 { 275 {
273 struct timespec64 ts = {.tv_sec = sec, 276 struct timespec64 ts = {.tv_sec = sec, .tv_nsec = nsec};
274 277
275 if (!timespec64_valid(&ts)) 278 if (!timespec64_valid(&ts))
276 return -EINVAL; 279 return -EINVAL;
277 280
278 /* Optimize for the zero timeout value 281 /* Optimize for the zero timeout value here */
279 if (!sec && !nsec) { 282 if (!sec && !nsec) {
280 to->tv_sec = to->tv_nsec = 0; 283 to->tv_sec = to->tv_nsec = 0;
281 } else { 284 } else {
282 ktime_get_ts64(to); 285 ktime_get_ts64(to);
283 *to = timespec64_add_safe(*to, 286 *to = timespec64_add_safe(*to, ts);
284 } 287 }
285 return 0; 288 return 0;
286 } 289 }
287 290
288 enum poll_time_type { 291 enum poll_time_type {
289 PT_TIMEVAL = 0, 292 PT_TIMEVAL = 0,
290 PT_OLD_TIMEVAL = 1, 293 PT_OLD_TIMEVAL = 1,
291 PT_TIMESPEC = 2, 294 PT_TIMESPEC = 2,
292 PT_OLD_TIMESPEC = 3, 295 PT_OLD_TIMESPEC = 3,
293 }; 296 };
294 297
295 static int poll_select_finish(struct timespec6 298 static int poll_select_finish(struct timespec64 *end_time,
296 void __user *p, 299 void __user *p,
297 enum poll_time_t 300 enum poll_time_type pt_type, int ret)
298 { 301 {
299 struct timespec64 rts; 302 struct timespec64 rts;
300 303
301 restore_saved_sigmask_unless(ret == -E 304 restore_saved_sigmask_unless(ret == -ERESTARTNOHAND);
302 305
303 if (!p) 306 if (!p)
304 return ret; 307 return ret;
305 308
306 if (current->personality & STICKY_TIME 309 if (current->personality & STICKY_TIMEOUTS)
307 goto sticky; 310 goto sticky;
308 311
309 /* No update for zero timeout */ 312 /* No update for zero timeout */
310 if (!end_time->tv_sec && !end_time->tv 313 if (!end_time->tv_sec && !end_time->tv_nsec)
311 return ret; 314 return ret;
312 315
313 ktime_get_ts64(&rts); 316 ktime_get_ts64(&rts);
314 rts = timespec64_sub(*end_time, rts); 317 rts = timespec64_sub(*end_time, rts);
315 if (rts.tv_sec < 0) 318 if (rts.tv_sec < 0)
316 rts.tv_sec = rts.tv_nsec = 0; 319 rts.tv_sec = rts.tv_nsec = 0;
317 320
318 321
319 switch (pt_type) { 322 switch (pt_type) {
320 case PT_TIMEVAL: 323 case PT_TIMEVAL:
321 { 324 {
322 struct __kernel_old_ti 325 struct __kernel_old_timeval rtv;
323 326
324 if (sizeof(rtv) > size 327 if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
325 memset(&rtv, 0 328 memset(&rtv, 0, sizeof(rtv));
326 rtv.tv_sec = rts.tv_se 329 rtv.tv_sec = rts.tv_sec;
327 rtv.tv_usec = rts.tv_n 330 rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
328 if (!copy_to_user(p, & 331 if (!copy_to_user(p, &rtv, sizeof(rtv)))
329 return ret; 332 return ret;
330 } 333 }
331 break; 334 break;
332 case PT_OLD_TIMEVAL: 335 case PT_OLD_TIMEVAL:
333 { 336 {
334 struct old_timeval32 r 337 struct old_timeval32 rtv;
335 338
336 rtv.tv_sec = rts.tv_se 339 rtv.tv_sec = rts.tv_sec;
337 rtv.tv_usec = rts.tv_n 340 rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
338 if (!copy_to_user(p, & 341 if (!copy_to_user(p, &rtv, sizeof(rtv)))
339 return ret; 342 return ret;
340 } 343 }
341 break; 344 break;
342 case PT_TIMESPEC: 345 case PT_TIMESPEC:
343 if (!put_timespec64(&rts, p)) 346 if (!put_timespec64(&rts, p))
344 return ret; 347 return ret;
345 break; 348 break;
346 case PT_OLD_TIMESPEC: 349 case PT_OLD_TIMESPEC:
347 if (!put_old_timespec32(&rts, 350 if (!put_old_timespec32(&rts, p))
348 return ret; 351 return ret;
349 break; 352 break;
350 default: 353 default:
351 BUG(); 354 BUG();
352 } 355 }
353 /* 356 /*
354 * If an application puts its timeval 357 * If an application puts its timeval in read-only memory, we
355 * don't want the Linux-specific updat 358 * don't want the Linux-specific update to the timeval to
356 * cause a fault after the select has 359 * cause a fault after the select has completed
357 * successfully. However, because we'r 360 * successfully. However, because we're not updating the
358 * timeval, we can't restart the syste 361 * timeval, we can't restart the system call.
359 */ 362 */
360 363
361 sticky: 364 sticky:
362 if (ret == -ERESTARTNOHAND) 365 if (ret == -ERESTARTNOHAND)
363 ret = -EINTR; 366 ret = -EINTR;
364 return ret; 367 return ret;
365 } 368 }
366 369
367 /* 370 /*
368 * Scalable version of the fd_set. 371 * Scalable version of the fd_set.
369 */ 372 */
370 373
371 typedef struct { 374 typedef struct {
372 unsigned long *in, *out, *ex; 375 unsigned long *in, *out, *ex;
373 unsigned long *res_in, *res_out, *res_ 376 unsigned long *res_in, *res_out, *res_ex;
374 } fd_set_bits; 377 } fd_set_bits;
375 378
376 /* 379 /*
377 * How many longwords for "nr" bits? 380 * How many longwords for "nr" bits?
378 */ 381 */
379 #define FDS_BITPERLONG (8*sizeof(long)) 382 #define FDS_BITPERLONG (8*sizeof(long))
380 #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG- 383 #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
381 #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof( 384 #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long))
382 385
383 /* 386 /*
384 * Use "unsigned long" accesses to let user-mo 387 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
385 */ 388 */
386 static inline 389 static inline
387 int get_fd_set(unsigned long nr, void __user * 390 int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
388 { 391 {
389 nr = FDS_BYTES(nr); 392 nr = FDS_BYTES(nr);
390 if (ufdset) 393 if (ufdset)
391 return copy_from_user(fdset, u 394 return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
392 395
393 memset(fdset, 0, nr); 396 memset(fdset, 0, nr);
394 return 0; 397 return 0;
395 } 398 }
396 399
397 static inline unsigned long __must_check 400 static inline unsigned long __must_check
398 set_fd_set(unsigned long nr, void __user *ufds 401 set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
399 { 402 {
400 if (ufdset) 403 if (ufdset)
401 return __copy_to_user(ufdset, 404 return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
402 return 0; 405 return 0;
403 } 406 }
404 407
405 static inline 408 static inline
406 void zero_fd_set(unsigned long nr, unsigned lo 409 void zero_fd_set(unsigned long nr, unsigned long *fdset)
407 { 410 {
408 memset(fdset, 0, FDS_BYTES(nr)); 411 memset(fdset, 0, FDS_BYTES(nr));
409 } 412 }
410 413
411 #define FDS_IN(fds, n) (fds->in + n) 414 #define FDS_IN(fds, n) (fds->in + n)
412 #define FDS_OUT(fds, n) (fds->out + n) 415 #define FDS_OUT(fds, n) (fds->out + n)
413 #define FDS_EX(fds, n) (fds->ex + n) 416 #define FDS_EX(fds, n) (fds->ex + n)
414 417
415 #define BITS(fds, n) (*FDS_IN(fds, n)|*FDS_ 418 #define BITS(fds, n) (*FDS_IN(fds, n)|*FDS_OUT(fds, n)|*FDS_EX(fds, n))
416 419
417 static int max_select_fd(unsigned long n, fd_s 420 static int max_select_fd(unsigned long n, fd_set_bits *fds)
418 { 421 {
419 unsigned long *open_fds; 422 unsigned long *open_fds;
420 unsigned long set; 423 unsigned long set;
421 int max; 424 int max;
422 struct fdtable *fdt; 425 struct fdtable *fdt;
423 426
424 /* handle last in-complete long-word f 427 /* handle last in-complete long-word first */
425 set = ~(~0UL << (n & (BITS_PER_LONG-1) 428 set = ~(~0UL << (n & (BITS_PER_LONG-1)));
426 n /= BITS_PER_LONG; 429 n /= BITS_PER_LONG;
427 fdt = files_fdtable(current->files); 430 fdt = files_fdtable(current->files);
428 open_fds = fdt->open_fds + n; 431 open_fds = fdt->open_fds + n;
429 max = 0; 432 max = 0;
430 if (set) { 433 if (set) {
431 set &= BITS(fds, n); 434 set &= BITS(fds, n);
432 if (set) { 435 if (set) {
433 if (!(set & ~*open_fds 436 if (!(set & ~*open_fds))
434 goto get_max; 437 goto get_max;
435 return -EBADF; 438 return -EBADF;
436 } 439 }
437 } 440 }
438 while (n) { 441 while (n) {
439 open_fds--; 442 open_fds--;
440 n--; 443 n--;
441 set = BITS(fds, n); 444 set = BITS(fds, n);
442 if (!set) 445 if (!set)
443 continue; 446 continue;
444 if (set & ~*open_fds) 447 if (set & ~*open_fds)
445 return -EBADF; 448 return -EBADF;
446 if (max) 449 if (max)
447 continue; 450 continue;
448 get_max: 451 get_max:
449 do { 452 do {
450 max++; 453 max++;
451 set >>= 1; 454 set >>= 1;
452 } while (set); 455 } while (set);
453 max += n * BITS_PER_LONG; 456 max += n * BITS_PER_LONG;
454 } 457 }
455 458
456 return max; 459 return max;
457 } 460 }
458 461
459 #define POLLIN_SET (EPOLLRDNORM | EPOLLRDBAND 462 #define POLLIN_SET (EPOLLRDNORM | EPOLLRDBAND | EPOLLIN | EPOLLHUP | EPOLLERR |\
460 EPOLLNVAL) 463 EPOLLNVAL)
461 #define POLLOUT_SET (EPOLLWRBAND | EPOLLWRNORM 464 #define POLLOUT_SET (EPOLLWRBAND | EPOLLWRNORM | EPOLLOUT | EPOLLERR |\
462 EPOLLNVAL) 465 EPOLLNVAL)
463 #define POLLEX_SET (EPOLLPRI | EPOLLNVAL) 466 #define POLLEX_SET (EPOLLPRI | EPOLLNVAL)
464 467
465 static inline void wait_key_set(poll_table *wa 468 static inline void wait_key_set(poll_table *wait, unsigned long in,
466 unsigned long 469 unsigned long out, unsigned long bit,
467 __poll_t ll_fl 470 __poll_t ll_flag)
468 { 471 {
469 wait->_key = POLLEX_SET | ll_flag; 472 wait->_key = POLLEX_SET | ll_flag;
470 if (in & bit) 473 if (in & bit)
471 wait->_key |= POLLIN_SET; 474 wait->_key |= POLLIN_SET;
472 if (out & bit) 475 if (out & bit)
473 wait->_key |= POLLOUT_SET; 476 wait->_key |= POLLOUT_SET;
474 } 477 }
475 478
476 static noinline_for_stack int do_select(int n, 479 static noinline_for_stack int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time)
477 { 480 {
478 ktime_t expire, *to = NULL; 481 ktime_t expire, *to = NULL;
479 struct poll_wqueues table; 482 struct poll_wqueues table;
480 poll_table *wait; 483 poll_table *wait;
481 int retval, i, timed_out = 0; 484 int retval, i, timed_out = 0;
482 u64 slack = 0; 485 u64 slack = 0;
483 __poll_t busy_flag = net_busy_loop_on( 486 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
484 unsigned long busy_start = 0; 487 unsigned long busy_start = 0;
485 488
486 rcu_read_lock(); 489 rcu_read_lock();
487 retval = max_select_fd(n, fds); 490 retval = max_select_fd(n, fds);
488 rcu_read_unlock(); 491 rcu_read_unlock();
489 492
490 if (retval < 0) 493 if (retval < 0)
491 return retval; 494 return retval;
492 n = retval; 495 n = retval;
493 496
494 poll_initwait(&table); 497 poll_initwait(&table);
495 wait = &table.pt; 498 wait = &table.pt;
496 if (end_time && !end_time->tv_sec && ! 499 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
497 wait->_qproc = NULL; 500 wait->_qproc = NULL;
498 timed_out = 1; 501 timed_out = 1;
499 } 502 }
500 503
501 if (end_time && !timed_out) 504 if (end_time && !timed_out)
502 slack = select_estimate_accura 505 slack = select_estimate_accuracy(end_time);
503 506
504 retval = 0; 507 retval = 0;
505 for (;;) { 508 for (;;) {
506 unsigned long *rinp, *routp, * 509 unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp;
507 bool can_busy_loop = false; 510 bool can_busy_loop = false;
508 511
509 inp = fds->in; outp = fds->out 512 inp = fds->in; outp = fds->out; exp = fds->ex;
510 rinp = fds->res_in; routp = fd 513 rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex;
511 514
512 for (i = 0; i < n; ++rinp, ++r 515 for (i = 0; i < n; ++rinp, ++routp, ++rexp) {
513 unsigned long in, out, 516 unsigned long in, out, ex, all_bits, bit = 1, j;
514 unsigned long res_in = 517 unsigned long res_in = 0, res_out = 0, res_ex = 0;
515 __poll_t mask; 518 __poll_t mask;
516 519
517 in = *inp++; out = *ou 520 in = *inp++; out = *outp++; ex = *exp++;
518 all_bits = in | out | 521 all_bits = in | out | ex;
519 if (all_bits == 0) { 522 if (all_bits == 0) {
520 i += BITS_PER_ 523 i += BITS_PER_LONG;
521 continue; 524 continue;
522 } 525 }
523 526
524 for (j = 0; j < BITS_P 527 for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) {
525 struct fd f; 528 struct fd f;
526 if (i >= n) 529 if (i >= n)
527 break; 530 break;
528 if (!(bit & al 531 if (!(bit & all_bits))
529 contin 532 continue;
530 mask = EPOLLNV 533 mask = EPOLLNVAL;
531 f = fdget(i); 534 f = fdget(i);
532 if (fd_file(f) !! 535 if (f.file) {
533 wait_k 536 wait_key_set(wait, in, out, bit,
534 537 busy_flag);
535 mask = !! 538 mask = vfs_poll(f.file, wait);
536 539
537 fdput( 540 fdput(f);
538 } 541 }
539 if ((mask & PO 542 if ((mask & POLLIN_SET) && (in & bit)) {
540 res_in 543 res_in |= bit;
541 retval 544 retval++;
542 wait-> 545 wait->_qproc = NULL;
543 } 546 }
544 if ((mask & PO 547 if ((mask & POLLOUT_SET) && (out & bit)) {
545 res_ou 548 res_out |= bit;
546 retval 549 retval++;
547 wait-> 550 wait->_qproc = NULL;
548 } 551 }
549 if ((mask & PO 552 if ((mask & POLLEX_SET) && (ex & bit)) {
550 res_ex 553 res_ex |= bit;
551 retval 554 retval++;
552 wait-> 555 wait->_qproc = NULL;
553 } 556 }
554 /* got somethi 557 /* got something, stop busy polling */
555 if (retval) { 558 if (retval) {
556 can_bu 559 can_busy_loop = false;
557 busy_f 560 busy_flag = 0;
558 561
559 /* 562 /*
560 * only rememb 563 * only remember a returned
561 * POLL_BUSY_L 564 * POLL_BUSY_LOOP if we asked for it
562 */ 565 */
563 } else if (bus 566 } else if (busy_flag & mask)
564 can_bu 567 can_busy_loop = true;
565 568
566 } 569 }
567 if (res_in) 570 if (res_in)
568 *rinp = res_in 571 *rinp = res_in;
569 if (res_out) 572 if (res_out)
570 *routp = res_o 573 *routp = res_out;
571 if (res_ex) 574 if (res_ex)
572 *rexp = res_ex 575 *rexp = res_ex;
573 cond_resched(); 576 cond_resched();
574 } 577 }
575 wait->_qproc = NULL; 578 wait->_qproc = NULL;
576 if (retval || timed_out || sig 579 if (retval || timed_out || signal_pending(current))
577 break; 580 break;
578 if (table.error) { 581 if (table.error) {
579 retval = table.error; 582 retval = table.error;
580 break; 583 break;
581 } 584 }
582 585
583 /* only if found POLL_BUSY_LOO 586 /* only if found POLL_BUSY_LOOP sockets && not out of time */
584 if (can_busy_loop && !need_res 587 if (can_busy_loop && !need_resched()) {
585 if (!busy_start) { 588 if (!busy_start) {
586 busy_start = b 589 busy_start = busy_loop_current_time();
587 continue; 590 continue;
588 } 591 }
589 if (!busy_loop_timeout 592 if (!busy_loop_timeout(busy_start))
590 continue; 593 continue;
591 } 594 }
592 busy_flag = 0; 595 busy_flag = 0;
593 596
594 /* 597 /*
595 * If this is the first loop a 598 * If this is the first loop and we have a timeout
596 * given, then we convert to k 599 * given, then we convert to ktime_t and set the to
597 * pointer to the expiry value 600 * pointer to the expiry value.
598 */ 601 */
599 if (end_time && !to) { 602 if (end_time && !to) {
600 expire = timespec64_to 603 expire = timespec64_to_ktime(*end_time);
601 to = &expire; 604 to = &expire;
602 } 605 }
603 606
604 if (!poll_schedule_timeout(&ta 607 if (!poll_schedule_timeout(&table, TASK_INTERRUPTIBLE,
605 to, 608 to, slack))
606 timed_out = 1; 609 timed_out = 1;
607 } 610 }
608 611
609 poll_freewait(&table); 612 poll_freewait(&table);
610 613
611 return retval; 614 return retval;
612 } 615 }
613 616
614 /* 617 /*
615 * We can actually return ERESTARTSYS instead 618 * We can actually return ERESTARTSYS instead of EINTR, but I'd
616 * like to be certain this leads to no problem 619 * like to be certain this leads to no problems. So I return
617 * EINTR just for safety. 620 * EINTR just for safety.
618 * 621 *
619 * Update: ERESTARTSYS breaks at least the xvi 622 * Update: ERESTARTSYS breaks at least the xview clock binary, so
620 * I'm trying ERESTARTNOHAND which restart onl 623 * I'm trying ERESTARTNOHAND which restart only when you want to.
621 */ 624 */
622 int core_sys_select(int n, fd_set __user *inp, 625 int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
623 fd_set __user *exp, 626 fd_set __user *exp, struct timespec64 *end_time)
624 { 627 {
625 fd_set_bits fds; 628 fd_set_bits fds;
626 void *bits; 629 void *bits;
627 int ret, max_fds; 630 int ret, max_fds;
628 size_t size, alloc_size; 631 size_t size, alloc_size;
629 struct fdtable *fdt; 632 struct fdtable *fdt;
630 /* Allocate small arguments on the sta 633 /* Allocate small arguments on the stack to save memory and be faster */
631 long stack_fds[SELECT_STACK_ALLOC/size 634 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];
632 635
633 ret = -EINVAL; 636 ret = -EINVAL;
634 if (n < 0) 637 if (n < 0)
635 goto out_nofds; 638 goto out_nofds;
636 639
637 /* max_fds can increase, so grab it on 640 /* max_fds can increase, so grab it once to avoid race */
638 rcu_read_lock(); 641 rcu_read_lock();
639 fdt = files_fdtable(current->files); 642 fdt = files_fdtable(current->files);
640 max_fds = fdt->max_fds; 643 max_fds = fdt->max_fds;
641 rcu_read_unlock(); 644 rcu_read_unlock();
642 if (n > max_fds) 645 if (n > max_fds)
643 n = max_fds; 646 n = max_fds;
644 647
645 /* 648 /*
646 * We need 6 bitmaps (in/out/ex for bo 649 * We need 6 bitmaps (in/out/ex for both incoming and outgoing),
647 * since we used fdset we need to allo 650 * since we used fdset we need to allocate memory in units of
648 * long-words. 651 * long-words.
649 */ 652 */
650 size = FDS_BYTES(n); 653 size = FDS_BYTES(n);
651 bits = stack_fds; 654 bits = stack_fds;
652 if (size > sizeof(stack_fds) / 6) { 655 if (size > sizeof(stack_fds) / 6) {
653 /* Not enough space in on-stac 656 /* Not enough space in on-stack array; must use kmalloc */
654 ret = -ENOMEM; 657 ret = -ENOMEM;
655 if (size > (SIZE_MAX / 6)) 658 if (size > (SIZE_MAX / 6))
656 goto out_nofds; 659 goto out_nofds;
657 660
658 alloc_size = 6 * size; 661 alloc_size = 6 * size;
659 bits = kvmalloc(alloc_size, GF 662 bits = kvmalloc(alloc_size, GFP_KERNEL);
660 if (!bits) 663 if (!bits)
661 goto out_nofds; 664 goto out_nofds;
662 } 665 }
663 fds.in = bits; 666 fds.in = bits;
664 fds.out = bits + size; 667 fds.out = bits + size;
665 fds.ex = bits + 2*size; 668 fds.ex = bits + 2*size;
666 fds.res_in = bits + 3*size; 669 fds.res_in = bits + 3*size;
667 fds.res_out = bits + 4*size; 670 fds.res_out = bits + 4*size;
668 fds.res_ex = bits + 5*size; 671 fds.res_ex = bits + 5*size;
669 672
670 if ((ret = get_fd_set(n, inp, fds.in)) 673 if ((ret = get_fd_set(n, inp, fds.in)) ||
671 (ret = get_fd_set(n, outp, fds.out 674 (ret = get_fd_set(n, outp, fds.out)) ||
672 (ret = get_fd_set(n, exp, fds.ex)) 675 (ret = get_fd_set(n, exp, fds.ex)))
673 goto out; 676 goto out;
674 zero_fd_set(n, fds.res_in); 677 zero_fd_set(n, fds.res_in);
675 zero_fd_set(n, fds.res_out); 678 zero_fd_set(n, fds.res_out);
676 zero_fd_set(n, fds.res_ex); 679 zero_fd_set(n, fds.res_ex);
677 680
678 ret = do_select(n, &fds, end_time); 681 ret = do_select(n, &fds, end_time);
679 682
680 if (ret < 0) 683 if (ret < 0)
681 goto out; 684 goto out;
682 if (!ret) { 685 if (!ret) {
683 ret = -ERESTARTNOHAND; 686 ret = -ERESTARTNOHAND;
684 if (signal_pending(current)) 687 if (signal_pending(current))
685 goto out; 688 goto out;
686 ret = 0; 689 ret = 0;
687 } 690 }
688 691
689 if (set_fd_set(n, inp, fds.res_in) || 692 if (set_fd_set(n, inp, fds.res_in) ||
690 set_fd_set(n, outp, fds.res_out) | 693 set_fd_set(n, outp, fds.res_out) ||
691 set_fd_set(n, exp, fds.res_ex)) 694 set_fd_set(n, exp, fds.res_ex))
692 ret = -EFAULT; 695 ret = -EFAULT;
693 696
694 out: 697 out:
695 if (bits != stack_fds) 698 if (bits != stack_fds)
696 kvfree(bits); 699 kvfree(bits);
697 out_nofds: 700 out_nofds:
698 return ret; 701 return ret;
699 } 702 }
700 703
701 static int kern_select(int n, fd_set __user *i 704 static int kern_select(int n, fd_set __user *inp, fd_set __user *outp,
702 fd_set __user *exp, str 705 fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
703 { 706 {
704 struct timespec64 end_time, *to = NULL 707 struct timespec64 end_time, *to = NULL;
705 struct __kernel_old_timeval tv; 708 struct __kernel_old_timeval tv;
706 int ret; 709 int ret;
707 710
708 if (tvp) { 711 if (tvp) {
709 if (copy_from_user(&tv, tvp, s 712 if (copy_from_user(&tv, tvp, sizeof(tv)))
710 return -EFAULT; 713 return -EFAULT;
711 714
712 to = &end_time; 715 to = &end_time;
713 if (poll_select_set_timeout(to 716 if (poll_select_set_timeout(to,
714 tv.tv_sec + (t 717 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
715 (tv.tv_usec % 718 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
716 return -EINVAL; 719 return -EINVAL;
717 } 720 }
718 721
719 ret = core_sys_select(n, inp, outp, ex 722 ret = core_sys_select(n, inp, outp, exp, to);
720 return poll_select_finish(&end_time, t 723 return poll_select_finish(&end_time, tvp, PT_TIMEVAL, ret);
721 } 724 }
722 725
723 SYSCALL_DEFINE5(select, int, n, fd_set __user 726 SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp,
724 fd_set __user *, exp, struct _ 727 fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp)
725 { 728 {
726 return kern_select(n, inp, outp, exp, 729 return kern_select(n, inp, outp, exp, tvp);
727 } 730 }
728 731
729 static long do_pselect(int n, fd_set __user *i 732 static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
730 fd_set __user *exp, voi 733 fd_set __user *exp, void __user *tsp,
731 const sigset_t __user * 734 const sigset_t __user *sigmask, size_t sigsetsize,
732 enum poll_time_type typ 735 enum poll_time_type type)
733 { 736 {
734 struct timespec64 ts, end_time, *to = 737 struct timespec64 ts, end_time, *to = NULL;
735 int ret; 738 int ret;
736 739
737 if (tsp) { 740 if (tsp) {
738 switch (type) { 741 switch (type) {
739 case PT_TIMESPEC: 742 case PT_TIMESPEC:
740 if (get_timespec64(&ts 743 if (get_timespec64(&ts, tsp))
741 return -EFAULT 744 return -EFAULT;
742 break; 745 break;
743 case PT_OLD_TIMESPEC: 746 case PT_OLD_TIMESPEC:
744 if (get_old_timespec32 747 if (get_old_timespec32(&ts, tsp))
745 return -EFAULT 748 return -EFAULT;
746 break; 749 break;
747 default: 750 default:
748 BUG(); 751 BUG();
749 } 752 }
750 753
751 to = &end_time; 754 to = &end_time;
752 if (poll_select_set_timeout(to 755 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
753 return -EINVAL; 756 return -EINVAL;
754 } 757 }
755 758
756 ret = set_user_sigmask(sigmask, sigset 759 ret = set_user_sigmask(sigmask, sigsetsize);
757 if (ret) 760 if (ret)
758 return ret; 761 return ret;
759 762
760 ret = core_sys_select(n, inp, outp, ex 763 ret = core_sys_select(n, inp, outp, exp, to);
761 return poll_select_finish(&end_time, t 764 return poll_select_finish(&end_time, tsp, type, ret);
762 } 765 }
763 766
764 /* 767 /*
765 * Most architectures can't handle 7-argument 768 * Most architectures can't handle 7-argument syscalls. So we provide a
766 * 6-argument version where the sixth argument 769 * 6-argument version where the sixth argument is a pointer to a structure
767 * which has a pointer to the sigset_t itself 770 * which has a pointer to the sigset_t itself followed by a size_t containing
768 * the sigset size. 771 * the sigset size.
769 */ 772 */
770 struct sigset_argpack { 773 struct sigset_argpack {
771 sigset_t __user *p; 774 sigset_t __user *p;
772 size_t size; 775 size_t size;
773 }; 776 };
774 777
775 static inline int get_sigset_argpack(struct si 778 static inline int get_sigset_argpack(struct sigset_argpack *to,
776 struct si 779 struct sigset_argpack __user *from)
777 { 780 {
778 // the path is hot enough for overhead 781 // the path is hot enough for overhead of copy_from_user() to matter
779 if (from) { 782 if (from) {
780 if (can_do_masked_user_access( !! 783 if (!user_read_access_begin(from, sizeof(*from)))
781 from = masked_user_acc <<
782 else if (!user_read_access_beg <<
783 return -EFAULT; 784 return -EFAULT;
784 unsafe_get_user(to->p, &from-> 785 unsafe_get_user(to->p, &from->p, Efault);
785 unsafe_get_user(to->size, &fro 786 unsafe_get_user(to->size, &from->size, Efault);
786 user_read_access_end(); 787 user_read_access_end();
787 } 788 }
788 return 0; 789 return 0;
789 Efault: 790 Efault:
790 user_access_end(); 791 user_access_end();
791 return -EFAULT; 792 return -EFAULT;
792 } 793 }
793 794
794 SYSCALL_DEFINE6(pselect6, int, n, fd_set __use 795 SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp,
795 fd_set __user *, exp, struct _ 796 fd_set __user *, exp, struct __kernel_timespec __user *, tsp,
796 void __user *, sig) 797 void __user *, sig)
797 { 798 {
798 struct sigset_argpack x = {NULL, 0}; 799 struct sigset_argpack x = {NULL, 0};
799 800
800 if (get_sigset_argpack(&x, sig)) 801 if (get_sigset_argpack(&x, sig))
801 return -EFAULT; 802 return -EFAULT;
802 803
803 return do_pselect(n, inp, outp, exp, t 804 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC);
804 } 805 }
805 806
806 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defi 807 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
807 808
808 SYSCALL_DEFINE6(pselect6_time32, int, n, fd_se 809 SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, outp,
809 fd_set __user *, exp, struct o 810 fd_set __user *, exp, struct old_timespec32 __user *, tsp,
810 void __user *, sig) 811 void __user *, sig)
811 { 812 {
812 struct sigset_argpack x = {NULL, 0}; 813 struct sigset_argpack x = {NULL, 0};
813 814
814 if (get_sigset_argpack(&x, sig)) 815 if (get_sigset_argpack(&x, sig))
815 return -EFAULT; 816 return -EFAULT;
816 817
817 return do_pselect(n, inp, outp, exp, t 818 return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC);
818 } 819 }
819 820
820 #endif 821 #endif
821 822
822 #ifdef __ARCH_WANT_SYS_OLD_SELECT 823 #ifdef __ARCH_WANT_SYS_OLD_SELECT
823 struct sel_arg_struct { 824 struct sel_arg_struct {
824 unsigned long n; 825 unsigned long n;
825 fd_set __user *inp, *outp, *exp; 826 fd_set __user *inp, *outp, *exp;
826 struct __kernel_old_timeval __user *tv 827 struct __kernel_old_timeval __user *tvp;
827 }; 828 };
828 829
829 SYSCALL_DEFINE1(old_select, struct sel_arg_str 830 SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg)
830 { 831 {
831 struct sel_arg_struct a; 832 struct sel_arg_struct a;
832 833
833 if (copy_from_user(&a, arg, sizeof(a)) 834 if (copy_from_user(&a, arg, sizeof(a)))
834 return -EFAULT; 835 return -EFAULT;
835 return kern_select(a.n, a.inp, a.outp, 836 return kern_select(a.n, a.inp, a.outp, a.exp, a.tvp);
836 } 837 }
837 #endif 838 #endif
838 839
839 struct poll_list { 840 struct poll_list {
840 struct poll_list *next; 841 struct poll_list *next;
841 unsigned int len; !! 842 int len;
842 struct pollfd entries[] __counted_by(l !! 843 struct pollfd entries[];
843 }; 844 };
844 845
845 #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(st 846 #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd))
846 847
847 /* 848 /*
848 * Fish for pollable events on the pollfd->fd 849 * Fish for pollable events on the pollfd->fd file descriptor. We're only
849 * interested in events matching the pollfd->e 850 * interested in events matching the pollfd->events mask, and the result
850 * matching that mask is both recorded in poll 851 * matching that mask is both recorded in pollfd->revents and returned. The
851 * pwait poll_table will be used by the fd-pro 852 * pwait poll_table will be used by the fd-provided poll handler for waiting,
852 * if pwait->_qproc is non-NULL. 853 * if pwait->_qproc is non-NULL.
853 */ 854 */
854 static inline __poll_t do_pollfd(struct pollfd 855 static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait,
855 bool *can 856 bool *can_busy_poll,
856 __poll_t 857 __poll_t busy_flag)
857 { 858 {
858 int fd = pollfd->fd; 859 int fd = pollfd->fd;
859 __poll_t mask = 0, filter; 860 __poll_t mask = 0, filter;
860 struct fd f; 861 struct fd f;
861 862
862 if (fd < 0) 863 if (fd < 0)
863 goto out; 864 goto out;
864 mask = EPOLLNVAL; 865 mask = EPOLLNVAL;
865 f = fdget(fd); 866 f = fdget(fd);
866 if (!fd_file(f)) !! 867 if (!f.file)
867 goto out; 868 goto out;
868 869
869 /* userland u16 ->events contains POLL 870 /* userland u16 ->events contains POLL... bitmap */
870 filter = demangle_poll(pollfd->events) 871 filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP;
871 pwait->_key = filter | busy_flag; 872 pwait->_key = filter | busy_flag;
872 mask = vfs_poll(fd_file(f), pwait); !! 873 mask = vfs_poll(f.file, pwait);
873 if (mask & busy_flag) 874 if (mask & busy_flag)
874 *can_busy_poll = true; 875 *can_busy_poll = true;
875 mask &= filter; /* Mask out un 876 mask &= filter; /* Mask out unneeded events. */
876 fdput(f); 877 fdput(f);
877 878
878 out: 879 out:
879 /* ... and so does ->revents */ 880 /* ... and so does ->revents */
880 pollfd->revents = mangle_poll(mask); 881 pollfd->revents = mangle_poll(mask);
881 return mask; 882 return mask;
882 } 883 }
883 884
884 static int do_poll(struct poll_list *list, str 885 static int do_poll(struct poll_list *list, struct poll_wqueues *wait,
885 struct timespec64 *end_time 886 struct timespec64 *end_time)
886 { 887 {
887 poll_table* pt = &wait->pt; 888 poll_table* pt = &wait->pt;
888 ktime_t expire, *to = NULL; 889 ktime_t expire, *to = NULL;
889 int timed_out = 0, count = 0; 890 int timed_out = 0, count = 0;
890 u64 slack = 0; 891 u64 slack = 0;
891 __poll_t busy_flag = net_busy_loop_on( 892 __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
892 unsigned long busy_start = 0; 893 unsigned long busy_start = 0;
893 894
894 /* Optimise the no-wait case */ 895 /* Optimise the no-wait case */
895 if (end_time && !end_time->tv_sec && ! 896 if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
896 pt->_qproc = NULL; 897 pt->_qproc = NULL;
897 timed_out = 1; 898 timed_out = 1;
898 } 899 }
899 900
900 if (end_time && !timed_out) 901 if (end_time && !timed_out)
901 slack = select_estimate_accura 902 slack = select_estimate_accuracy(end_time);
902 903
903 for (;;) { 904 for (;;) {
904 struct poll_list *walk; 905 struct poll_list *walk;
905 bool can_busy_loop = false; 906 bool can_busy_loop = false;
906 907
907 for (walk = list; walk != NULL 908 for (walk = list; walk != NULL; walk = walk->next) {
908 struct pollfd * pfd, * 909 struct pollfd * pfd, * pfd_end;
909 910
910 pfd = walk->entries; 911 pfd = walk->entries;
911 pfd_end = pfd + walk-> 912 pfd_end = pfd + walk->len;
912 for (; pfd != pfd_end; 913 for (; pfd != pfd_end; pfd++) {
913 /* 914 /*
914 * Fish for ev 915 * Fish for events. If we found one, record it
915 * and kill po 916 * and kill poll_table->_qproc, so we don't
916 * needlessly 917 * needlessly register any other waiters after
917 * this. They' 918 * this. They'll get immediately deregistered
918 * when we bre 919 * when we break out and return.
919 */ 920 */
920 if (do_pollfd( 921 if (do_pollfd(pfd, pt, &can_busy_loop,
921 922 busy_flag)) {
922 count+ 923 count++;
923 pt->_q 924 pt->_qproc = NULL;
924 /* fou 925 /* found something, stop busy polling */
925 busy_f 926 busy_flag = 0;
926 can_bu 927 can_busy_loop = false;
927 } 928 }
928 } 929 }
929 } 930 }
930 /* 931 /*
931 * All waiters have already be 932 * All waiters have already been registered, so don't provide
932 * a poll_table->_qproc to the 933 * a poll_table->_qproc to them on the next loop iteration.
933 */ 934 */
934 pt->_qproc = NULL; 935 pt->_qproc = NULL;
935 if (!count) { 936 if (!count) {
936 count = wait->error; 937 count = wait->error;
937 if (signal_pending(cur 938 if (signal_pending(current))
938 count = -EREST 939 count = -ERESTARTNOHAND;
939 } 940 }
940 if (count || timed_out) 941 if (count || timed_out)
941 break; 942 break;
942 943
943 /* only if found POLL_BUSY_LOO 944 /* only if found POLL_BUSY_LOOP sockets && not out of time */
944 if (can_busy_loop && !need_res 945 if (can_busy_loop && !need_resched()) {
945 if (!busy_start) { 946 if (!busy_start) {
946 busy_start = b 947 busy_start = busy_loop_current_time();
947 continue; 948 continue;
948 } 949 }
949 if (!busy_loop_timeout 950 if (!busy_loop_timeout(busy_start))
950 continue; 951 continue;
951 } 952 }
952 busy_flag = 0; 953 busy_flag = 0;
953 954
954 /* 955 /*
955 * If this is the first loop a 956 * If this is the first loop and we have a timeout
956 * given, then we convert to k 957 * given, then we convert to ktime_t and set the to
957 * pointer to the expiry value 958 * pointer to the expiry value.
958 */ 959 */
959 if (end_time && !to) { 960 if (end_time && !to) {
960 expire = timespec64_to 961 expire = timespec64_to_ktime(*end_time);
961 to = &expire; 962 to = &expire;
962 } 963 }
963 964
964 if (!poll_schedule_timeout(wai 965 if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack))
965 timed_out = 1; 966 timed_out = 1;
966 } 967 }
967 return count; 968 return count;
968 } 969 }
969 970
970 #define N_STACK_PPS ((sizeof(stack_pps) - size 971 #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \
971 sizeof(struct pollfd)) 972 sizeof(struct pollfd))
972 973
973 static int do_sys_poll(struct pollfd __user *u 974 static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
974 struct timespec64 *end_time) 975 struct timespec64 *end_time)
975 { 976 {
976 struct poll_wqueues table; 977 struct poll_wqueues table;
977 int err = -EFAULT, fdcount; !! 978 int err = -EFAULT, fdcount, len;
978 /* Allocate small arguments on the sta 979 /* Allocate small arguments on the stack to save memory and be
979 faster - use long to make sure the 980 faster - use long to make sure the buffer is aligned properly
980 on 64 bit archs to avoid unaligned 981 on 64 bit archs to avoid unaligned access */
981 long stack_pps[POLL_STACK_ALLOC/sizeof 982 long stack_pps[POLL_STACK_ALLOC/sizeof(long)];
982 struct poll_list *const head = (struct 983 struct poll_list *const head = (struct poll_list *)stack_pps;
983 struct poll_list *walk = head; 984 struct poll_list *walk = head;
984 unsigned int todo = nfds; !! 985 unsigned long todo = nfds;
985 unsigned int len; <<
986 986
987 if (nfds > rlimit(RLIMIT_NOFILE)) 987 if (nfds > rlimit(RLIMIT_NOFILE))
988 return -EINVAL; 988 return -EINVAL;
989 989
990 len = min_t(unsigned int, nfds, N_STAC 990 len = min_t(unsigned int, nfds, N_STACK_PPS);
991 for (;;) { 991 for (;;) {
992 walk->next = NULL; 992 walk->next = NULL;
993 walk->len = len; 993 walk->len = len;
994 if (!len) 994 if (!len)
995 break; 995 break;
996 996
997 if (copy_from_user(walk->entri 997 if (copy_from_user(walk->entries, ufds + nfds-todo,
998 sizeof 998 sizeof(struct pollfd) * walk->len))
999 goto out_fds; 999 goto out_fds;
1000 1000
1001 if (walk->len >= todo) <<
1002 break; <<
1003 todo -= walk->len; 1001 todo -= walk->len;
>> 1002 if (!todo)
>> 1003 break;
1004 1004
1005 len = min(todo, POLLFD_PER_PA 1005 len = min(todo, POLLFD_PER_PAGE);
1006 walk = walk->next = kmalloc(s 1006 walk = walk->next = kmalloc(struct_size(walk, entries, len),
1007 G 1007 GFP_KERNEL);
1008 if (!walk) { 1008 if (!walk) {
1009 err = -ENOMEM; 1009 err = -ENOMEM;
1010 goto out_fds; 1010 goto out_fds;
1011 } 1011 }
1012 } 1012 }
1013 1013
1014 poll_initwait(&table); 1014 poll_initwait(&table);
1015 fdcount = do_poll(head, &table, end_t 1015 fdcount = do_poll(head, &table, end_time);
1016 poll_freewait(&table); 1016 poll_freewait(&table);
1017 1017
1018 if (!user_write_access_begin(ufds, nf 1018 if (!user_write_access_begin(ufds, nfds * sizeof(*ufds)))
1019 goto out_fds; 1019 goto out_fds;
1020 1020
1021 for (walk = head; walk; walk = walk-> 1021 for (walk = head; walk; walk = walk->next) {
1022 struct pollfd *fds = walk->en 1022 struct pollfd *fds = walk->entries;
1023 unsigned int j; !! 1023 int j;
1024 1024
1025 for (j = walk->len; j; fds++, 1025 for (j = walk->len; j; fds++, ufds++, j--)
1026 unsafe_put_user(fds-> 1026 unsafe_put_user(fds->revents, &ufds->revents, Efault);
1027 } 1027 }
1028 user_write_access_end(); 1028 user_write_access_end();
1029 1029
1030 err = fdcount; 1030 err = fdcount;
1031 out_fds: 1031 out_fds:
1032 walk = head->next; 1032 walk = head->next;
1033 while (walk) { 1033 while (walk) {
1034 struct poll_list *pos = walk; 1034 struct poll_list *pos = walk;
1035 walk = walk->next; 1035 walk = walk->next;
1036 kfree(pos); 1036 kfree(pos);
1037 } 1037 }
1038 1038
1039 return err; 1039 return err;
1040 1040
1041 Efault: 1041 Efault:
1042 user_write_access_end(); 1042 user_write_access_end();
1043 err = -EFAULT; 1043 err = -EFAULT;
1044 goto out_fds; 1044 goto out_fds;
1045 } 1045 }
1046 1046
1047 static long do_restart_poll(struct restart_bl 1047 static long do_restart_poll(struct restart_block *restart_block)
1048 { 1048 {
1049 struct pollfd __user *ufds = restart_ 1049 struct pollfd __user *ufds = restart_block->poll.ufds;
1050 int nfds = restart_block->poll.nfds; 1050 int nfds = restart_block->poll.nfds;
1051 struct timespec64 *to = NULL, end_tim 1051 struct timespec64 *to = NULL, end_time;
1052 int ret; 1052 int ret;
1053 1053
1054 if (restart_block->poll.has_timeout) 1054 if (restart_block->poll.has_timeout) {
1055 end_time.tv_sec = restart_blo 1055 end_time.tv_sec = restart_block->poll.tv_sec;
1056 end_time.tv_nsec = restart_bl 1056 end_time.tv_nsec = restart_block->poll.tv_nsec;
1057 to = &end_time; 1057 to = &end_time;
1058 } 1058 }
1059 1059
1060 ret = do_sys_poll(ufds, nfds, to); 1060 ret = do_sys_poll(ufds, nfds, to);
1061 1061
1062 if (ret == -ERESTARTNOHAND) 1062 if (ret == -ERESTARTNOHAND)
1063 ret = set_restart_fn(restart_ 1063 ret = set_restart_fn(restart_block, do_restart_poll);
1064 1064
1065 return ret; 1065 return ret;
1066 } 1066 }
1067 1067
1068 SYSCALL_DEFINE3(poll, struct pollfd __user *, 1068 SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
1069 int, timeout_msecs) 1069 int, timeout_msecs)
1070 { 1070 {
1071 struct timespec64 end_time, *to = NUL 1071 struct timespec64 end_time, *to = NULL;
1072 int ret; 1072 int ret;
1073 1073
1074 if (timeout_msecs >= 0) { 1074 if (timeout_msecs >= 0) {
1075 to = &end_time; 1075 to = &end_time;
1076 poll_select_set_timeout(to, t 1076 poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC,
1077 NSEC_PER_MSEC * (time 1077 NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC));
1078 } 1078 }
1079 1079
1080 ret = do_sys_poll(ufds, nfds, to); 1080 ret = do_sys_poll(ufds, nfds, to);
1081 1081
1082 if (ret == -ERESTARTNOHAND) { 1082 if (ret == -ERESTARTNOHAND) {
1083 struct restart_block *restart 1083 struct restart_block *restart_block;
1084 1084
1085 restart_block = ¤t->res 1085 restart_block = ¤t->restart_block;
1086 restart_block->poll.ufds = uf 1086 restart_block->poll.ufds = ufds;
1087 restart_block->poll.nfds = nf 1087 restart_block->poll.nfds = nfds;
1088 1088
1089 if (timeout_msecs >= 0) { 1089 if (timeout_msecs >= 0) {
1090 restart_block->poll.t 1090 restart_block->poll.tv_sec = end_time.tv_sec;
1091 restart_block->poll.t 1091 restart_block->poll.tv_nsec = end_time.tv_nsec;
1092 restart_block->poll.h 1092 restart_block->poll.has_timeout = 1;
1093 } else 1093 } else
1094 restart_block->poll.h 1094 restart_block->poll.has_timeout = 0;
1095 1095
1096 ret = set_restart_fn(restart_ 1096 ret = set_restart_fn(restart_block, do_restart_poll);
1097 } 1097 }
1098 return ret; 1098 return ret;
1099 } 1099 }
1100 1100
1101 SYSCALL_DEFINE5(ppoll, struct pollfd __user * 1101 SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
1102 struct __kernel_timespec __us 1102 struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask,
1103 size_t, sigsetsize) 1103 size_t, sigsetsize)
1104 { 1104 {
1105 struct timespec64 ts, end_time, *to = 1105 struct timespec64 ts, end_time, *to = NULL;
1106 int ret; 1106 int ret;
1107 1107
1108 if (tsp) { 1108 if (tsp) {
1109 if (get_timespec64(&ts, tsp)) 1109 if (get_timespec64(&ts, tsp))
1110 return -EFAULT; 1110 return -EFAULT;
1111 1111
1112 to = &end_time; 1112 to = &end_time;
1113 if (poll_select_set_timeout(t 1113 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1114 return -EINVAL; 1114 return -EINVAL;
1115 } 1115 }
1116 1116
1117 ret = set_user_sigmask(sigmask, sigse 1117 ret = set_user_sigmask(sigmask, sigsetsize);
1118 if (ret) 1118 if (ret)
1119 return ret; 1119 return ret;
1120 1120
1121 ret = do_sys_poll(ufds, nfds, to); 1121 ret = do_sys_poll(ufds, nfds, to);
1122 return poll_select_finish(&end_time, 1122 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret);
1123 } 1123 }
1124 1124
1125 #if defined(CONFIG_COMPAT_32BIT_TIME) && !def 1125 #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
1126 1126
1127 SYSCALL_DEFINE5(ppoll_time32, struct pollfd _ 1127 SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds,
1128 struct old_timespec32 __user 1128 struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask,
1129 size_t, sigsetsize) 1129 size_t, sigsetsize)
1130 { 1130 {
1131 struct timespec64 ts, end_time, *to = 1131 struct timespec64 ts, end_time, *to = NULL;
1132 int ret; 1132 int ret;
1133 1133
1134 if (tsp) { 1134 if (tsp) {
1135 if (get_old_timespec32(&ts, t 1135 if (get_old_timespec32(&ts, tsp))
1136 return -EFAULT; 1136 return -EFAULT;
1137 1137
1138 to = &end_time; 1138 to = &end_time;
1139 if (poll_select_set_timeout(t 1139 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1140 return -EINVAL; 1140 return -EINVAL;
1141 } 1141 }
1142 1142
1143 ret = set_user_sigmask(sigmask, sigse 1143 ret = set_user_sigmask(sigmask, sigsetsize);
1144 if (ret) 1144 if (ret)
1145 return ret; 1145 return ret;
1146 1146
1147 ret = do_sys_poll(ufds, nfds, to); 1147 ret = do_sys_poll(ufds, nfds, to);
1148 return poll_select_finish(&end_time, 1148 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret);
1149 } 1149 }
1150 #endif 1150 #endif
1151 1151
1152 #ifdef CONFIG_COMPAT 1152 #ifdef CONFIG_COMPAT
1153 #define __COMPAT_NFDBITS (8 * sizeof(co 1153 #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t))
1154 1154
1155 /* 1155 /*
1156 * Ooo, nasty. We need here to frob 32-bit u 1156 * Ooo, nasty. We need here to frob 32-bit unsigned longs to
1157 * 64-bit unsigned longs. 1157 * 64-bit unsigned longs.
1158 */ 1158 */
1159 static 1159 static
1160 int compat_get_fd_set(unsigned long nr, compa 1160 int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
1161 unsigned long *fdset) 1161 unsigned long *fdset)
1162 { 1162 {
1163 if (ufdset) { 1163 if (ufdset) {
1164 return compat_get_bitmap(fdse 1164 return compat_get_bitmap(fdset, ufdset, nr);
1165 } else { 1165 } else {
1166 zero_fd_set(nr, fdset); 1166 zero_fd_set(nr, fdset);
1167 return 0; 1167 return 0;
1168 } 1168 }
1169 } 1169 }
1170 1170
1171 static 1171 static
1172 int compat_set_fd_set(unsigned long nr, compa 1172 int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
1173 unsigned long *fdset) 1173 unsigned long *fdset)
1174 { 1174 {
1175 if (!ufdset) 1175 if (!ufdset)
1176 return 0; 1176 return 0;
1177 return compat_put_bitmap(ufdset, fdse 1177 return compat_put_bitmap(ufdset, fdset, nr);
1178 } 1178 }
1179 1179
1180 1180
1181 /* 1181 /*
1182 * This is a virtual copy of sys_select from 1182 * This is a virtual copy of sys_select from fs/select.c and probably
1183 * should be compared to it from time to time 1183 * should be compared to it from time to time
1184 */ 1184 */
1185 1185
1186 /* 1186 /*
1187 * We can actually return ERESTARTSYS instead 1187 * We can actually return ERESTARTSYS instead of EINTR, but I'd
1188 * like to be certain this leads to no proble 1188 * like to be certain this leads to no problems. So I return
1189 * EINTR just for safety. 1189 * EINTR just for safety.
1190 * 1190 *
1191 * Update: ERESTARTSYS breaks at least the xv 1191 * Update: ERESTARTSYS breaks at least the xview clock binary, so
1192 * I'm trying ERESTARTNOHAND which restart on 1192 * I'm trying ERESTARTNOHAND which restart only when you want to.
1193 */ 1193 */
1194 static int compat_core_sys_select(int n, comp 1194 static int compat_core_sys_select(int n, compat_ulong_t __user *inp,
1195 compat_ulong_t __user *outp, compat_u 1195 compat_ulong_t __user *outp, compat_ulong_t __user *exp,
1196 struct timespec64 *end_time) 1196 struct timespec64 *end_time)
1197 { 1197 {
1198 fd_set_bits fds; 1198 fd_set_bits fds;
1199 void *bits; 1199 void *bits;
1200 int size, max_fds, ret = -EINVAL; 1200 int size, max_fds, ret = -EINVAL;
1201 struct fdtable *fdt; 1201 struct fdtable *fdt;
1202 long stack_fds[SELECT_STACK_ALLOC/siz 1202 long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];
1203 1203
1204 if (n < 0) 1204 if (n < 0)
1205 goto out_nofds; 1205 goto out_nofds;
1206 1206
1207 /* max_fds can increase, so grab it o 1207 /* max_fds can increase, so grab it once to avoid race */
1208 rcu_read_lock(); 1208 rcu_read_lock();
1209 fdt = files_fdtable(current->files); 1209 fdt = files_fdtable(current->files);
1210 max_fds = fdt->max_fds; 1210 max_fds = fdt->max_fds;
1211 rcu_read_unlock(); 1211 rcu_read_unlock();
1212 if (n > max_fds) 1212 if (n > max_fds)
1213 n = max_fds; 1213 n = max_fds;
1214 1214
1215 /* 1215 /*
1216 * We need 6 bitmaps (in/out/ex for b 1216 * We need 6 bitmaps (in/out/ex for both incoming and outgoing),
1217 * since we used fdset we need to all 1217 * since we used fdset we need to allocate memory in units of
1218 * long-words. 1218 * long-words.
1219 */ 1219 */
1220 size = FDS_BYTES(n); 1220 size = FDS_BYTES(n);
1221 bits = stack_fds; 1221 bits = stack_fds;
1222 if (size > sizeof(stack_fds) / 6) { 1222 if (size > sizeof(stack_fds) / 6) {
1223 bits = kmalloc_array(6, size, 1223 bits = kmalloc_array(6, size, GFP_KERNEL);
1224 ret = -ENOMEM; 1224 ret = -ENOMEM;
1225 if (!bits) 1225 if (!bits)
1226 goto out_nofds; 1226 goto out_nofds;
1227 } 1227 }
1228 fds.in = (unsigned long *) bits 1228 fds.in = (unsigned long *) bits;
1229 fds.out = (unsigned long *) (bits 1229 fds.out = (unsigned long *) (bits + size);
1230 fds.ex = (unsigned long *) (bits 1230 fds.ex = (unsigned long *) (bits + 2*size);
1231 fds.res_in = (unsigned long *) (bits 1231 fds.res_in = (unsigned long *) (bits + 3*size);
1232 fds.res_out = (unsigned long *) (bits 1232 fds.res_out = (unsigned long *) (bits + 4*size);
1233 fds.res_ex = (unsigned long *) (bits 1233 fds.res_ex = (unsigned long *) (bits + 5*size);
1234 1234
1235 if ((ret = compat_get_fd_set(n, inp, 1235 if ((ret = compat_get_fd_set(n, inp, fds.in)) ||
1236 (ret = compat_get_fd_set(n, outp, 1236 (ret = compat_get_fd_set(n, outp, fds.out)) ||
1237 (ret = compat_get_fd_set(n, exp, 1237 (ret = compat_get_fd_set(n, exp, fds.ex)))
1238 goto out; 1238 goto out;
1239 zero_fd_set(n, fds.res_in); 1239 zero_fd_set(n, fds.res_in);
1240 zero_fd_set(n, fds.res_out); 1240 zero_fd_set(n, fds.res_out);
1241 zero_fd_set(n, fds.res_ex); 1241 zero_fd_set(n, fds.res_ex);
1242 1242
1243 ret = do_select(n, &fds, end_time); 1243 ret = do_select(n, &fds, end_time);
1244 1244
1245 if (ret < 0) 1245 if (ret < 0)
1246 goto out; 1246 goto out;
1247 if (!ret) { 1247 if (!ret) {
1248 ret = -ERESTARTNOHAND; 1248 ret = -ERESTARTNOHAND;
1249 if (signal_pending(current)) 1249 if (signal_pending(current))
1250 goto out; 1250 goto out;
1251 ret = 0; 1251 ret = 0;
1252 } 1252 }
1253 1253
1254 if (compat_set_fd_set(n, inp, fds.res 1254 if (compat_set_fd_set(n, inp, fds.res_in) ||
1255 compat_set_fd_set(n, outp, fds.re 1255 compat_set_fd_set(n, outp, fds.res_out) ||
1256 compat_set_fd_set(n, exp, fds.res 1256 compat_set_fd_set(n, exp, fds.res_ex))
1257 ret = -EFAULT; 1257 ret = -EFAULT;
1258 out: 1258 out:
1259 if (bits != stack_fds) 1259 if (bits != stack_fds)
1260 kfree(bits); 1260 kfree(bits);
1261 out_nofds: 1261 out_nofds:
1262 return ret; 1262 return ret;
1263 } 1263 }
1264 1264
1265 static int do_compat_select(int n, compat_ulo 1265 static int do_compat_select(int n, compat_ulong_t __user *inp,
1266 compat_ulong_t __user *outp, compat_u 1266 compat_ulong_t __user *outp, compat_ulong_t __user *exp,
1267 struct old_timeval32 __user *tvp) 1267 struct old_timeval32 __user *tvp)
1268 { 1268 {
1269 struct timespec64 end_time, *to = NUL 1269 struct timespec64 end_time, *to = NULL;
1270 struct old_timeval32 tv; 1270 struct old_timeval32 tv;
1271 int ret; 1271 int ret;
1272 1272
1273 if (tvp) { 1273 if (tvp) {
1274 if (copy_from_user(&tv, tvp, 1274 if (copy_from_user(&tv, tvp, sizeof(tv)))
1275 return -EFAULT; 1275 return -EFAULT;
1276 1276
1277 to = &end_time; 1277 to = &end_time;
1278 if (poll_select_set_timeout(t 1278 if (poll_select_set_timeout(to,
1279 tv.tv_sec + ( 1279 tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
1280 (tv.tv_usec % 1280 (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
1281 return -EINVAL; 1281 return -EINVAL;
1282 } 1282 }
1283 1283
1284 ret = compat_core_sys_select(n, inp, 1284 ret = compat_core_sys_select(n, inp, outp, exp, to);
1285 return poll_select_finish(&end_time, 1285 return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret);
1286 } 1286 }
1287 1287
1288 COMPAT_SYSCALL_DEFINE5(select, int, n, compat 1288 COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp,
1289 compat_ulong_t __user *, outp, compat 1289 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
1290 struct old_timeval32 __user *, tvp) 1290 struct old_timeval32 __user *, tvp)
1291 { 1291 {
1292 return do_compat_select(n, inp, outp, 1292 return do_compat_select(n, inp, outp, exp, tvp);
1293 } 1293 }
1294 1294
1295 struct compat_sel_arg_struct { 1295 struct compat_sel_arg_struct {
1296 compat_ulong_t n; 1296 compat_ulong_t n;
1297 compat_uptr_t inp; 1297 compat_uptr_t inp;
1298 compat_uptr_t outp; 1298 compat_uptr_t outp;
1299 compat_uptr_t exp; 1299 compat_uptr_t exp;
1300 compat_uptr_t tvp; 1300 compat_uptr_t tvp;
1301 }; 1301 };
1302 1302
1303 COMPAT_SYSCALL_DEFINE1(old_select, struct com 1303 COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg)
1304 { 1304 {
1305 struct compat_sel_arg_struct a; 1305 struct compat_sel_arg_struct a;
1306 1306
1307 if (copy_from_user(&a, arg, sizeof(a) 1307 if (copy_from_user(&a, arg, sizeof(a)))
1308 return -EFAULT; 1308 return -EFAULT;
1309 return do_compat_select(a.n, compat_p 1309 return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp),
1310 compat_ptr(a. 1310 compat_ptr(a.exp), compat_ptr(a.tvp));
1311 } 1311 }
1312 1312
1313 static long do_compat_pselect(int n, compat_u 1313 static long do_compat_pselect(int n, compat_ulong_t __user *inp,
1314 compat_ulong_t __user *outp, compat_u 1314 compat_ulong_t __user *outp, compat_ulong_t __user *exp,
1315 void __user *tsp, compat_sigset_t __u 1315 void __user *tsp, compat_sigset_t __user *sigmask,
1316 compat_size_t sigsetsize, enum poll_t 1316 compat_size_t sigsetsize, enum poll_time_type type)
1317 { 1317 {
1318 struct timespec64 ts, end_time, *to = 1318 struct timespec64 ts, end_time, *to = NULL;
1319 int ret; 1319 int ret;
1320 1320
1321 if (tsp) { 1321 if (tsp) {
1322 switch (type) { 1322 switch (type) {
1323 case PT_OLD_TIMESPEC: 1323 case PT_OLD_TIMESPEC:
1324 if (get_old_timespec3 1324 if (get_old_timespec32(&ts, tsp))
1325 return -EFAUL 1325 return -EFAULT;
1326 break; 1326 break;
1327 case PT_TIMESPEC: 1327 case PT_TIMESPEC:
1328 if (get_timespec64(&t 1328 if (get_timespec64(&ts, tsp))
1329 return -EFAUL 1329 return -EFAULT;
1330 break; 1330 break;
1331 default: 1331 default:
1332 BUG(); 1332 BUG();
1333 } 1333 }
1334 1334
1335 to = &end_time; 1335 to = &end_time;
1336 if (poll_select_set_timeout(t 1336 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1337 return -EINVAL; 1337 return -EINVAL;
1338 } 1338 }
1339 1339
1340 ret = set_compat_user_sigmask(sigmask 1340 ret = set_compat_user_sigmask(sigmask, sigsetsize);
1341 if (ret) 1341 if (ret)
1342 return ret; 1342 return ret;
1343 1343
1344 ret = compat_core_sys_select(n, inp, 1344 ret = compat_core_sys_select(n, inp, outp, exp, to);
1345 return poll_select_finish(&end_time, 1345 return poll_select_finish(&end_time, tsp, type, ret);
1346 } 1346 }
1347 1347
1348 struct compat_sigset_argpack { 1348 struct compat_sigset_argpack {
1349 compat_uptr_t p; 1349 compat_uptr_t p;
1350 compat_size_t size; 1350 compat_size_t size;
1351 }; 1351 };
1352 static inline int get_compat_sigset_argpack(s 1352 static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,
1353 s 1353 struct compat_sigset_argpack __user *from)
1354 { 1354 {
1355 if (from) { 1355 if (from) {
1356 if (!user_read_access_begin(f 1356 if (!user_read_access_begin(from, sizeof(*from)))
1357 return -EFAULT; 1357 return -EFAULT;
1358 unsafe_get_user(to->p, &from- 1358 unsafe_get_user(to->p, &from->p, Efault);
1359 unsafe_get_user(to->size, &fr 1359 unsafe_get_user(to->size, &from->size, Efault);
1360 user_read_access_end(); 1360 user_read_access_end();
1361 } 1361 }
1362 return 0; 1362 return 0;
1363 Efault: 1363 Efault:
1364 user_access_end(); 1364 user_access_end();
1365 return -EFAULT; 1365 return -EFAULT;
1366 } 1366 }
1367 1367
1368 COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, 1368 COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp,
1369 compat_ulong_t __user *, outp, compat 1369 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
1370 struct __kernel_timespec __user *, ts 1370 struct __kernel_timespec __user *, tsp, void __user *, sig)
1371 { 1371 {
1372 struct compat_sigset_argpack x = {0, 1372 struct compat_sigset_argpack x = {0, 0};
1373 1373
1374 if (get_compat_sigset_argpack(&x, sig 1374 if (get_compat_sigset_argpack(&x, sig))
1375 return -EFAULT; 1375 return -EFAULT;
1376 1376
1377 return do_compat_pselect(n, inp, outp 1377 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),
1378 x.size, PT_T 1378 x.size, PT_TIMESPEC);
1379 } 1379 }
1380 1380
1381 #if defined(CONFIG_COMPAT_32BIT_TIME) 1381 #if defined(CONFIG_COMPAT_32BIT_TIME)
1382 1382
1383 COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, 1383 COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp,
1384 compat_ulong_t __user *, outp, compat 1384 compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
1385 struct old_timespec32 __user *, tsp, 1385 struct old_timespec32 __user *, tsp, void __user *, sig)
1386 { 1386 {
1387 struct compat_sigset_argpack x = {0, 1387 struct compat_sigset_argpack x = {0, 0};
1388 1388
1389 if (get_compat_sigset_argpack(&x, sig 1389 if (get_compat_sigset_argpack(&x, sig))
1390 return -EFAULT; 1390 return -EFAULT;
1391 1391
1392 return do_compat_pselect(n, inp, outp 1392 return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),
1393 x.size, PT_O 1393 x.size, PT_OLD_TIMESPEC);
1394 } 1394 }
1395 1395
1396 #endif 1396 #endif
1397 1397
1398 #if defined(CONFIG_COMPAT_32BIT_TIME) 1398 #if defined(CONFIG_COMPAT_32BIT_TIME)
1399 COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct p 1399 COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds,
1400 unsigned int, nfds, struct old_times 1400 unsigned int, nfds, struct old_timespec32 __user *, tsp,
1401 const compat_sigset_t __user *, sigma 1401 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
1402 { 1402 {
1403 struct timespec64 ts, end_time, *to = 1403 struct timespec64 ts, end_time, *to = NULL;
1404 int ret; 1404 int ret;
1405 1405
1406 if (tsp) { 1406 if (tsp) {
1407 if (get_old_timespec32(&ts, t 1407 if (get_old_timespec32(&ts, tsp))
1408 return -EFAULT; 1408 return -EFAULT;
1409 1409
1410 to = &end_time; 1410 to = &end_time;
1411 if (poll_select_set_timeout(t 1411 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1412 return -EINVAL; 1412 return -EINVAL;
1413 } 1413 }
1414 1414
1415 ret = set_compat_user_sigmask(sigmask 1415 ret = set_compat_user_sigmask(sigmask, sigsetsize);
1416 if (ret) 1416 if (ret)
1417 return ret; 1417 return ret;
1418 1418
1419 ret = do_sys_poll(ufds, nfds, to); 1419 ret = do_sys_poll(ufds, nfds, to);
1420 return poll_select_finish(&end_time, 1420 return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret);
1421 } 1421 }
1422 #endif 1422 #endif
1423 1423
1424 /* New compat syscall for 64 bit time_t*/ 1424 /* New compat syscall for 64 bit time_t*/
1425 COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct p 1425 COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds,
1426 unsigned int, nfds, struct __kernel_ 1426 unsigned int, nfds, struct __kernel_timespec __user *, tsp,
1427 const compat_sigset_t __user *, sigma 1427 const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
1428 { 1428 {
1429 struct timespec64 ts, end_time, *to = 1429 struct timespec64 ts, end_time, *to = NULL;
1430 int ret; 1430 int ret;
1431 1431
1432 if (tsp) { 1432 if (tsp) {
1433 if (get_timespec64(&ts, tsp)) 1433 if (get_timespec64(&ts, tsp))
1434 return -EFAULT; 1434 return -EFAULT;
1435 1435
1436 to = &end_time; 1436 to = &end_time;
1437 if (poll_select_set_timeout(t 1437 if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1438 return -EINVAL; 1438 return -EINVAL;
1439 } 1439 }
1440 1440
1441 ret = set_compat_user_sigmask(sigmask 1441 ret = set_compat_user_sigmask(sigmask, sigsetsize);
1442 if (ret) 1442 if (ret)
1443 return ret; 1443 return ret;
1444 1444
1445 ret = do_sys_poll(ufds, nfds, to); 1445 ret = do_sys_poll(ufds, nfds, to);
1446 return poll_select_finish(&end_time, 1446 return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret);
1447 } 1447 }
1448 1448
1449 #endif 1449 #endif
1450 1450
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